Flap for a flap-type finishing wheel

ABSTRACT

There is disclosed a finishing wheel formed of an annulus of abrasive flaps. The flaps are of small width, typically about one-fourth to three-fourths inch. This width is not adequate to accommodate the flanges of the flanged end plates or flange discs to which the drive shaft for the wheels are secured if the end plates are mounted in the same way as they are for conventional wide wheels. The length of each flange is greater than one-half the width of the wheel. In the wheel disclosed the slots in the opposite surfaces of the core are displaced radially with respect to each other so that each need be only of sufficient depth to accommodate one flange without penetrating the annulus. This wheel is formed of an annulus of flaps having grooves or notches extending into opposite edges. The grooves in each are displaced so that no groove extending into one edge is coextensive with a groove extending into the opposite edge.

United States Patent Schaffner, III

14 1 Sept. 30, 1975 FLAP FOR A FLAP-TYPE FINISHING WHEEL [75] Inventor:Gus J. Schaffner, III, Pittsburgh, Pa.

[73] Assignee: Schaffner Manufacturing Company,

Inc., Pittsburgh. Pa.

[22] Filed: Mar. 17, I975 21 Appl. No.: 558,662

Related US. Application Data [62] Division of Ser. No. 259,538, June 5.1972, Pat, No.

[52] US. Cl. 51/394; 51/334; 51/395 [51] B24D 11/00; B24D 9/02 [58]Field of Search 5l/334337, 51/394, 395. 397; 15/230, 23012, 230.14,230.17, 230.19

[56] References Cited UNITED STATES PATENTS 3,191,350 6/1965 Yokel51/336 3,548,550 12/1970 McAleer 51/334 356L173 2/1971 Block 51/334Primur Examiner.lames L. Jones, Jr. Assistant E.\'umin er-Nicholas P.Godici Attorney, Agent, or Firm-Hymen Diamond [57] ABSTRACT There isdisclosed a finishing wheel formed of an annulus of abrasive flaps. Theflaps are of small width, typically about one-fourth to three-fourthsinch. This width is not adequate to accommodate the flanges of theflanged end plates or flange discs to which the drive shaft for thewheels are secured if the end plates are mounted in the same way as theyare for conventional wide wheels. The length of each flange is greaterthan one-half the width of the wheel. In the wheel disclosed the slotsin the opposite surfaces of the core are displaced radially with respectto each other so that each need be only of sufficient depth toaccommodate one flange without penetrating the annulus. This wheel isformed of an annulus of flaps having grooves or notches extending intoopposite edges. The grooves in each are displaced so that no grooveextending into one edge is coextensive with a groove extending into theopposite edge.

3 Claims, 8 Drawing Figures US. Patent Sept. 30,1975 3,908,319

FLAP FOR A FLAP-TYPE FINISHING WHEEL REFERENCE TO RELATED APPLICATIONSThis application is a division of application Ser. No. 259,538 filedJune 5, 1972 to Gus .l. Schaffner III for FINISHING, now US. Pat. No.3,890,119.

BACKGROUND OF THE INVENTION This invention relates to the art offinishing materials such as metal, wood or plastic and has particularrelationship to finishing wheels formed of an annulus of flaps. As usedin this application the word finishing includes within its scopepolishing, in whose practice there may be substantial removal ofmaterial, as well as buffing and coloring, in whose practice a sheen isimparted without substantial removal of material. The flaps may bestructured to meet the respective purposes of the wheels. In some casesthe flaps may be composed throughout of non-abrasive fabric. Typically,however, the flaps are of woven fabric abrasive on one surface andsmooth on the opposite surface. There are also wheels whose flaps areabrasive on both surfaces and wheels in which abrasive and non-abrasiveflaps or abrasive flaps of different grit size are interleaved or inwhich flaps of woven and non-woven fabric are interleaved, as disclosedin U.S. Pat. No. 3,706,167 granted Dec. 19, 1972 to Robert D. Schaffnerfor Finishing Apparatus. There are also wheels whose flaps are all ofnon-woven abrasive fabric.

The annulus of flaps has a core or hub at the center formed by bondingor securing together the radially inner ends of the flaps. The flapsextend freely from this core.

During a finishing operation a finishing wheel is rotated at a highspeed with the free ends of its flaps in contact with the work. Fordriving the wheel, end plates or flange discs are typically centrallydisposed in engagement with the core of the annulus and a drive shaftwhich passes through a bearing in the end plates is secured by nuts tothe end plates. (See, for example, end plates 91 and 93 FIG. 8 SchaffnerUS. Pat. No. 3,294,502). The end plates are provided with projections orflanges which engage circular slots in opposite core or hub surfaces ofthe annulus. Typically, the flanges penetrate to a depth of aboutone-fourth inch or more into the core.

This invention concerns itself with wheels having narrow flaps;typically flaps having a width of about onefourth or one-half inch andin some cases as high as three-fourths or one inch. Typically suchwheels are used in grinding the titanium blades of jet engines. In

' grinding such blades it is desirable that a blade be held duringgrinding so that it extends towards the hub or axis of the wheel. It isthen necessary that obstruction to the blade be avoided and that the hubof the annulus project from the opposite surfaces of the annulus aslittle as practicable.

It is necessary that the annulus of a wheel whose flaps are narrow beadapted to accommodate the flanges of the flange disc to achieve thispurpose, the flaps of wheels, whose flaps are narrow, are, in accordancewith the teachings of the prior art, T-shaped with the head of the T atthe core, and of substantial radial length and width. When such flapsare formed into an annulus, the annulus has a hub or core whichprotrudes from both opposite surfaces of the wheel. Typically, the headof the T may have a length of one-inch and a width of about one-inch andfor such flaps, a hub one-inch in radial length and one-quarter inch inheight on each side protrudes centrally from the annulus.

This prior-art practice results in a substantial cost in material. Atypical finishing wheel may have onethousand or more flaps which areformed of costly material. The additional material used to form theheads of the Ts of the flaps imposes a substantial increment in the costof the flaps. In addition, the protruding hub militates againsteffective processing of work pieces, such as the titanium blades of jetengines, which are held, during finishing, so that they extend towardsthe hub.

It is an object of this invention to overcome the disadvantages of theprior art by providing a unique flap to replace the T-shaped flap and ofsubstantially lower cost than the T-shaped flap, which flap with otherslike it shall be adapted to be formed into a finishing wheel,

consisting of an annulus of these unique flaps, in whose use obstructionto work pieces, extending inwardly towards the axis of the wheel, shallbe minimized.

SUMMARY OF THE INVENTION In accordance with this invention, there isprovided a narrow flap in the form of an elongated rectangle having inits edges near one end grooves extending into its opposite edges. Thegrooves in one edge are displaced along the length of the flap withrespect to the grooves in the opposite edge so that no grooves extendinginto opposite edges are coextensive. A plurality of these flaps areassembled into a finishing wheel formed of an annulus of these flapswith their grooves coextensive to form slots to accommodate flanges offlange discs for driving the wheel. The slots are radially displacedwith reference to each other. The slots can accommodate flangesexxtending into the annulus a distance equal to half or even a greaterfraction of the width of the flaps. When such a wheel is in use thereare no protruding hub parts to interfere with the ends of work pieces.This aspect of the invention is applicable to wheels of greater widththan one-fourth inch.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of thisinvention, both as to its organization and as to its method ofoperation, together with additional objects and advantages thereof,reference is made to the following description, taken in connection withthe accompanying drawing, in which:

FIG. 1 is a plan view of a finishing wheel formed of an annulus of flapsin accordance with this invention;

FIG. 2 is a view in section taken along line IIII of FIG. 1;

FIG. 3 is a fragmental view of a flap in accordance with this invention;

FIG. 4 is a fragmental view of a section of the annulus of a wheel asshown in FIG. 1 demonstrating the manner in which the core or hub isformed;

FIG. 5 is a plan view of a finishing wheel formed of an annulus ofdifferent flaps;

FIG. 6 is a view in section taken along line VIVI of FIG. 5; g

FIG. 7 is a fragmental view of a flap used in the wheel of FIG. 5; and

FIG. 8 is a fragmental view of a section of the annulus of the wheelshown in FIG. 5 demonstrating the manner in which the core or hub ismade.

DETAILED DESCRIPTION OF THE INVENTION The apparatus shown in FIGS. 1through 4 is a finishing wheel 11 having an annulus 13 of flaps 15 andflange discs or end plates 17 and 19 whose flanges 21 and 23 engagecircular slots 25 and 27 respectively in the hub 29 of the annulus. Theflap 15 embodying this invention has grooves 31 and 33 which form slots25 and 27 respectively when the flaps 15 are formed into an annulus. Thegrooves 31 and 33 are near the one end of the flap 15 which is disposedat the center of the annulus. The slots 25 and 27 are then radiallydisplaced with respect to each other, the slot 27 being nearer theperiphery than the slot 25. The flanges 21 and 23 are near theperipheries of the respective discs 21 and 23 so that disc 21 has asmaller diameter than disc 23. However, the discs may be of equaldiameter with the flange which engages the slot 25 at a smaller distancefrom the center of its disc than the flange which engages slot 27. Asshown in FIG. 2, the flange discs 17 and 19 are flush with the surfacesof the wheel 11.

In forming the annulus the flaps 15 are disposed on a projection such asthe flange 21 of disc 17 so that they extend radially side by side fromthis flange 21. After an annulus is formed, the flaps in one region areforced apart, and more flaps are inserted until the annulus is tight.After the annulus is formed an adhesive 41 (FIG. 4), typically an epoxyresin with a suitable hardener, is painted on the inner periphery of theannulus and the part of the annulus extending from the periphery andincluding, and extending just beyond, the slot 27. The adhesive 41 isdistributed over the inside of the slot. The annulus is then turned overand the adhesive 41 is painted over the part of the annulus extendingjust beyond the slot 25. The viscosity of the adhesive is set so thatthe adhesive penetrates (by capillarity) between the flaps 15. The slots25 and 27 are then coated with silicone rubber 43. The flange discs 17and 19 are then mounted on the annulus with their flanges 21 and 23engaging, and secured by the silicone rubber to, the slots 25 and 27 andthe adhesive 41 is cured to form the annulus 13 with a solid core. A

The disc 19 has a central cylindrical shell 45 which serves as a bearingfor the drive shaft (not shown). Typically, the shell 45 passes throughthe opening in disc 17. The drive shaft (not shown) is secured by nuts(not shown) which are screwed onto the shaft and engage the discs 25 and27. Lock washers (not shown) may be inserted between the nuts and thediscs 25 and 27.

In some situations the shell 45 may be omitted. In this case both discshave holes of the same diameter and the shaft (not shown) is supportedon the edges bounding the holes. To assure that the shaft is aligned,the wheels of this type are cured on a CALROD heater of outside diametersuch as to permit the wheel to be slipped over and aligned.

The apparatus shown in FIGS. 5 through 8 is a finishing wheel 51including an annulus 53 of flaps 55. The flaps 55 are of generallyL-shape each flap having a foot 57. The annulus formed of the flaps 55has, extending from one surface of, its hub or core a projection orflange 59 formed of the foot 57 of the L.

The wheel 51 includes a generally dish-shaped flange disc 61 having aflange 63. A cylindrical shell 65 extends from the center of disc 61 andserves as bearing for a drive shaft (not shown). A flange washer 67 issupported on the center of disc 61 with the stem 69 of the washer 67extending over the shell 65. The disc 61 contains a hub 71 of curedadhesive, typically an epoxy resin with a suitable hardener. The annulus53, the disc 61 and the washer 67 are secured together into a rigid unitby the adhesive 71 with the flange 59 in engagement with the flange 63.The drive shaft (not shown) is secured by nuts (not shown) which engagethe disc 61 and the flange 73 of the washer 67. The pressure on thewasher 67 by the nut is distributed over the surface of the washer andprevents the adhesive 71 from being crushed.

In forming the annulus 53 the disc 61 is placed on a surface with itsflange 63 upwardly. The flaps 55 are arranged side-by-side radially withtheir feet 57 engaging the flange 63 internally. When an annulus isformed, the flaps 55 are forced apart in one region and additional flaps55 inserted until the annulus 53 is tight. The inner periphery and thesurface opposite the flange 59 are then painted with an adhesive 81(FIG. 8), typically an epoxy resin with a suitable hardener; the surfacebeing painted to a distance just beyond the outer periphery of theflange 59. The annulus is then turned over and the circular stripdefined by the end of the foot and the inner periphery of the flange 59are painted with an adhesive. The adhesive has a viscosity such that itpenetrates by capillarity between the flaps 55. Silicone rubber 83 isthen deposited along the outer corners (the instep) of the core.

The annulus 53 is now placed on the disc 61 with its flange 59 engagingthe flange 63. The washer 67 is,

slipped over the shell 65 and adhesive is poured on the disc, and theadhesive between the flaps 55 of the annulus 53 and the poured adhesive71 are cured to form a core in the annulus 53 and the hub 71. Theadhesive 71 is essentially cast into a mold formed by the disc 61, thewasher 67 and the annulus 53.

While preferred embodiments of this invention have been disclosedherein, many modifications thereof are feasible. This invention then isnot to be restricted except insofar as is necessitated by the spirit ofthe prior art.

I claim:

1. A flap for a flap wheel comprising a strip of fabric having groovesextending into opposite edges of said strip near one end of said striptransversely to the long dimension thereof, said grooves being displacedalong the length of said strip with respect to each other so that nogroove extending into one edge is coextensive with a groove extendinginto the opposite edge.

2. The flap of claim 1 wherein the sum of the depths of the grooves issubstantially equal to the width of the flap.

3. The flap of claim 1 wherein there is only one groove extending intoeach of the annulus. =l i=

1. A flap for a flap wheel comprising a strip of fabric having groovesextending into opposite edges of said strip near one end of said striptransversely to the long dimension thereof, said grooves being displacedalong the length of said strip with respect to each other so that nogroove extending into one edge is coextensive with a groove extendinginto the opposite edge.
 2. The flap of claim 1 wherein the sum of thedepths of the grooves is substantially equal to the width of the flap.3. The flap of claim 1 wherein there is only one groove extending intoeach of the annulus.